The present invention relates to tip trailers, and in particular provides a low profile and lightweight tip trailer.
Tip trailers are regularly used in a wide range of applications, primarily in the earthmoving industry. For example, tip trailers may be used for transporting materials in civil contracting works such as construction or road works, or may be used to remove workings from a mine, or to deliver soil to private individuals such as landholders or farmers.
Conventional tip trailers usually lift a front end of a bin to cause a load to slide out a back of the truck, or, in the case of a xe2x80x98side tipperxe2x80x99, a side of the bin is lifted to cause the load to slide out an opposite side of the bin. Conventional tip trailers are usually of one of the following two types: xe2x80x9cchassis tipperxe2x80x9d or xe2x80x9ctip-over-axlexe2x80x9d. A chassis tipper is characterised by a chassis mounted on front and Year axles, the bin being mounted on the chassis such that when tipped, a front end of the bin rises, above the chassis and axles. A tip-over-axle style tip trailer is characterised in that the bin is mounted to the chassis and the axles such that when tipped, the chassis and even the front axle lift along with the bin, the tipping motion being about the rear axle.
Furthermore, in designing the bin of tip trailers, a number of limiting factors come into play. For example, the maximum width of the bin is often dictated by the width of public roads. In conventional tip trailers the useable width of the bin is further limited by vertical support members, usually of square cross sectional shape, which are located on the outside of the bin on either side of the bin. The vertical support members are required in order to provide sufficient robustness and rigidity to the skin of the bin so as to withstand the outward forces exerted when the bin is loaded. However the useable width of the bin is reduced by the transverse dimension of the vertical support members on either side.
Additionally, the maximum height of the bin can not be greater than the clearances of bridges and the like on public roads, and the height of the bin is preferably as small as possible so as to ease the loading of materials into the bin, for example by a loader, and to increase the stability of the tip trailer. However, conventional bin designs are hampered in this regard by the need for elements between the wheels and the floor of the bin. These elements include a chassis, suspension, hydraulic ram(s) and a turnplate. In particular, the turnplate must be sufficiently strong to withstand the forces created between the prime mover and the trailer during use, for example by acceleration and cornering, and therefore is typically quite bulky. The chassis typically includes a number of heavy beams extending along the length of the bin, which provide the primary structural strength of the tip trailer and support the bin. The presence of these elements causes the floor of the bin to be elevated above the top of the wheels. In known tip trailers the floor of the bin is usually higher than desirable above the top of the wheels.
Also, the length of the bin is preferably minimised in order to provide a short wheel base to increase stability of the bin both during travel and when tipping.
However, reducing the dimensions of the bin limits the volume of the bin. In order to move a given amount of material in the least number of loads it is desirable to load the bin as close as possible to the legal weight limit. However, where the material to be carried is not dense, the limited volume of the bin often results in a full load weighing significantly less than the legal weight limit, and so a larger number of loads are required, increasing the time and cost of transporting the material.
A further limitation placed on the design of tip trailers results from the conflicting requirements of (a) robustness and strength in the bin and (b) reducing the weight of the bin as much as possible. In order to provide sufficient strength and durability, practically all conventional tip trailers are heavier than is desirable. However, this increases fuel consumption and, due to the legal weight limit, reduces the weight of a load which may be carried.
According to a first aspect, the present invention provides a tip trailer including:
a bin having a floor, a front wall, side walls and a plurality of struts extending from the floor to substantially an upper extremity of the side walls;
one or more rear axles and wheels; and
tipping means operable to tip the bin;
wherein overhead beams for bearing the bin and a load of the bin are located substantially at an upper extremity of each side wall and extend substantially along a length of the bin, and wherein the floor is suspended from the overhead beams.
The floor may be suspended from the overhead beams by the struts and/or the walls.
The overhead beams are preferably supported by rear struts located proximate the rear axles, and by the front wall or struts proximate the front wall. Alternatively, the overhead beams may be supported at a front of the bin by the tipping means. The weight of the overhead beams is preferably transferred to the rear axles and to a turnplate.
The overhead beams provided in the present invention may act to support some or all of a load in the bin, permitting the absence of a chassis located beneath the floor of the bin, or alternatively permitting a significant reduction in size, weight, strength and load bearing ability of a chassis. The reduced size or absence of a chassis enables the floor of the bin to be situated significantly closer to the wheels than in prior art tip trailers, providing a low centre of gravity and improved stability.
The overhead beams are preferably located at an upper extremity of the side walls.
The tipping means may be operable to lift a front end of the bin, or alternatively, in xe2x80x98side tipperxe2x80x99 embodiments of the invention, to lift a side of the bin. The tipping means is preferably provided by one or more hydraulic rams.
Embodiments of the invention may further include large transverse trusses located under the floor between the front and rear axles. The transverse trusses are preferably configured to transfer a downward force exerted by a load in the bin to outer edges of the bin. As such transverse trusses are located between the front and rear axles, they may extend significantly below a height of the top of the wheels.
The tip trailer of the present invention permits the reduction in size or removal altogether of a chassis under the floor of the bin.
Preferred embodiments of the invention further include a low profile turnplate and a low profile drawbar. In particularly preferred embodiments, the low profile drawbar is hingedly connected at a front extremity to a tumplate-hitch and hingedly connected at a rear extremity of the drawbar to the bin.
The low profile drawbar should be of sufficient length relative to a tip height of the bin to permit tipping of the bin. The low profile drawbar may be hingedly connected to the turnplate-hitch and to the bin by known pin and sleeve arrangements.
The low profile drawbar is preferably effected by primary beams passing along an outer edge of the floor, and preferably situated at least partially above a height of the floor. This arrangement may be assisted by the side walls of the bin being angled such that, close to the floor, the side walls extend inwardly to meet the floor a distance from the edge of the bin. In such embodiments the floor is not as wide as the bin, but is of sufficient width to meet the angled portion of the sidewalls, thereby forming a longitudinally mitred corner where the floor and the sidewall meet. The low profile drawbar may then be adapted to fit around the mitred corner, and even to extend above the mitre, outside the bin wall. This reduces the portion of the low profile drawbar situated below a height of the floor, permitting the bin to be mounted such that the floor of the bin is located close to the top of the wheels.
The low profile drawbar preferably includes a number of secondary braces situated below the floor and extending between the primary beams. The secondary braces are preferably configured so as to provide stability and rigidity to the low profile drawbar. The secondary braces preferably have a small vertical dimension to permit the floor of the bin to be mounted close to the top of the wheels.
The turnplate-hitch is preferably of low profile, that is, having a small vertical dimension to permit the mounting of the bin such that the floor of the bin is close to the top of the wheels. The turnplate-hitch acts to transfer force between the turnplate and the low profile drawbar. Preferably, the turnplate-hitch transfers force between the turnplate and primary beams of the low profile drawbar.
According to a second aspect, the present invention provides a tip trailer including:
a bin having a floor, a front wall, side walls and a plurality of struts extending from the floor to substantially an upper extremity of the side walls;
one or more rear axles and wheels, and
tipping means operable to tip the bin;
the tip trailer being characterised by large transverse trusses located under the floor between the front and rear axles and configured to transfer a downward force exerted by a load in the bin to outer edges of the bin.
By transferring the load to an outer edge of the bin, the large transverse trusses permit the weight to be transferred by the side walls or by vertical struts to overhead beams.
According to a third aspect, the present invention provides a tip trailer including:
a bin having a floor, a front wall, side walls and a plurality of struts extending from the floor to substantially an upper extremity of the side walls;
one or more rear axles and wheels; and
tipping means operable to lift a front end of the bin;
the tip trailer being characterised in that at least one of the struts is positioned internally of the sidewalls and is adapted to divert material around the strut when the bin is tipped.
This arrangement provides a significant increase in the volume of the bin, as the xe2x80x98skinxe2x80x99 of the bin is situated at the outer edge of the bin, rather than internally relative to the vertical struts.
In the past it has been seen to be impractical to locate the vertical struts inwardly of the sidewalls of the bin, for instance due to material catching behind the vertical struts when the bin is tipped. However, it has now been realised that the volume of the bin can be significantly increased without creating this problem by providing the vertical struts internally to the sidewalls and configuring the vertical struts to divert material around the strut when the bin is tipped.
Preferably, in order to divert material around the vertical struts when the bin is tipped, each strut has a forward surface angled away from an adjacent sidewall. For example, each strut may have a triangular cross sectional shape, with the forward surface of the triangular strut forming an obtuse angle with the adjacent sidewall.
According to a fourth aspect, the present invention provides a tip trailer including:
a bin having a floor, a front wall, side walls and a plurality of struts extending from the floor to substantially an upper extremity of the side walls;
one or more rear axles and wheels which support the floor at a height above ground; and
tipping means operable to lift a front end of the bin;
the tip trailer being characterised by a, preferably low profile, drawbar hingedly connected at a front extremity to a tumplate-hitch and hingedly connected at a rear extremity of the drawbar to the bin, the low profile drawbar being situated at least partially above the height of the floor.
The low profile drawbar being situated at least partially above the height of the floor reduces the portion of the low profile drawbar situated below the height of the floor, permitting the bin to be mounted such that the floor of the bin is located close to the top of the wheels, thereby lowering a center of gravity of the tip trailer and increasing stability.
The low profile drawbar should be of sufficient length relative to a tip height of the bin to permit tipping of the bin. The low profile drawbar may be hingedly connected to the turnplate-hitch and to the bin by known pin and sleeve arrangements.
The low profile drawbar is preferably effected by primary beams passing along an outer edge of the floor, and preferably situated at least partially above a height of the floor. This arrangement may be assisted by sidewalls which are angled such that, close to the floor, the side wall extends inwardly to meet the floor a distance from the edge of the bin. In such embodiments the floor is not as wide as the bin, but is of sufficient width to meet the angled portion of the sidewalls, thereby forming a longitudinally mitred corner where the floor and the sidewall meet. The low profile drawbar may then be adapted to fit around the mitred corner, and even to extend above the mitre, outside the bin wall. This reduces the portion of the low profile drawbar situated below a height of the floor, and permits the bin to be mounted such that the floor of the bin is located close to the top of the wheels.
The low profile drawbar preferably includes a number of secondary struts situated below the floor and extending between the primary beams. The secondary struts are preferably configured so as to provide stability and rigidity to the low profile drawbar. The secondary struts preferably have a small vertical dimension to permit the floor of the bin to be mounted close to the top of the wheels.
A tumplate and tumplate-hitch are preferably provided and preferably are of low profile, that is, having a small vertical dimension to permit the mounting of the bin such that the floor of the bin is close to the top of the wheels. The tumplate-hitch acts to transfer force between the turnplate and the low profile drawbar. Preferably, the tumplate-hitch transfers force between the tumplate and primary beams of the low profile drawbar.
Embodiments of the present invention may include the features of one or more of the above aspects of the invention, as will be recognised by one skilled in the art. For instance, rear vertical beams supporting the overhead beam of the first aspect of the invention may be located inwardly of each sidewall and adapted to divert material around the beam, in accordance with the third aspect of the invention. Further, large transverse trusses may be provided, in which case the low profile drawbar preferably extends around a transverse extremity of each truss.
The tip trailer of any one of the above aspects of the invention may further include a tailgate extending across a rear end of the bin, attached by hinges so as to swing open when the bin is tipped to permit material to pass out of the bin, and to swing closed when the bin is not lifted to prevent material from exiting the bin. The tailgate may further include locking means to prevent unwanted movement of the tailgate. The movement of the tailgate may be controlled by one or more hydraulic rams.
The tip trailer of the present invention may include one or more front axles and wheels.
According to a fifth aspect, the present invention provides a side tipper including:
a bin having a floor, a front wall, a rear wall, one or more side walls and a plurality of struts extending from the floor to substantially an upper extremity of the walls;
one or more rear axles and wheels; and
tipping means operable to lift a side of the bin;
wherein overhead beams for bearing a load of the bin are located substantially at an upper extremity of each side of the bin and extend substantially along a length of the bin, and wherein the floor is suspended from the overhead beams.
The floor is preferably suspended from the overhead beams by one or more of the walls and/or the struts. The side tipper may also include one or more front axles and wheels.
The side tipper of the fifth aspect of the invention preferably includes a plurality of gates along a side of the bin. A plurality of gates may be desirable in cases where a storage vessel has a relatively narrow opening, such as a grain silo configured for a conventional rear end tip trailer. In such cases, a single gate may be opened at any one time in order to direct a portion of the load into the opening without spillage, after which the side tipper may be moved relative to the opening such that another gate may be opened to direct a further portion of the load into the narrow opening of the silo.
Preferred embodiments of the fifth aspect of the invention further include transverse trusses located under the floor between the front and rear axles. The transverse trusses are preferably configured to transfer a downward force exerted by a load in the bin to outer edges of the bin. As such transverse trusses are located between the front and rear axles, they may extend significantly below a height of the top of the wheels.
The overhead beams of the fifth aspect of the invention also overcome or ameliorate a significant problem in prior art side tippers, which can undergo significant twist or torque when the bin is tipped. This twist is often due to an uneven load distribution in the bin or to an uneven lifting force provided by two or more hydraulic tipping rams. Complex proportioning of the forces exerted by the rams is often the only solution to this problem. The overhead beams of the present invention significantly strengthen and stiffen the bin, which enables simple and relatively inexpensive hydraulics to be used. In embodiments where such are provided, large transverse trusses also assist in stiffening the bin and preventing twist in the bin during tipping.
The side tipper of the fifth aspect of the invention may further include a rear turnplate, such that one or more additional trailers may be connected in a B-double or road train arrangement. Such embodiments are particularly advantageous as a plurality of side tipper trailers may be loaded, transported and unloaded without the need for unhitching the trailers.